package validate import "net/url" var ( ErrInvalidURL Error = NewError("invalid URL") ) // URL validates that a string is an absolute URL (with a scheme) or an // absolute path, per net/url.ParseRequestURI. "example.com" with no // scheme is rejected. func URL(value string) error { if _, err := url.ParseRequestURI(value); err != nil { return ErrInvalidURL } return nil }